Revert "Remove gmp from AOS"

This reverts commit f37c97684f0910a3f241394549392f00145ab0f7.

We need gmp for SymEngine for symbolicmanipultion in C++

Change-Id: Ia13216d1715cf96944f7b4f422b7a799f921d4a4
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/third_party/gmp/mpf/sub_ui.c b/third_party/gmp/mpf/sub_ui.c
new file mode 100644
index 0000000..a23d2a8
--- /dev/null
+++ b/third_party/gmp/mpf/sub_ui.c
@@ -0,0 +1,50 @@
+/* mpf_sub_ui -- Subtract an unsigned integer from a float.
+
+Copyright 1993, 1994, 1996, 2001 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of either:
+
+  * the GNU Lesser General Public License as published by the Free
+    Software Foundation; either version 3 of the License, or (at your
+    option) any later version.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+#include "gmp-impl.h"
+
+void
+mpf_sub_ui (mpf_ptr sum, mpf_srcptr u, unsigned long int v)
+{
+  __mpf_struct vv;
+  mp_limb_t vl;
+
+  if (v == 0)
+    {
+      mpf_set (sum, u);
+      return;
+    }
+
+  vl = v;
+  vv._mp_size = 1;
+  vv._mp_d = &vl;
+  vv._mp_exp = 1;
+  mpf_sub (sum, u, &vv);
+}